Revolvers offer multiple advantages over auto-loading pistols, including increased reliability and simplicity of use. Yet, there are some advantages of auto-loading pistols over revolvers. One advantage of auto-loading pistols is that the one-piece construction of the barrel assembly prevents hot propulsion gases, resultant of firing the pistol, from leaking out in the direction of the user.
A chamber is the region of firearm which houses the cartridge. A cartridge contains the projectile or bullet, the cartridge case, propellant, and primer. When the propellant within a cartridge is ignited by the firing pin striking the primer, pressure builds until the projectile overcomes the friction from the cartridge case and starts traveling towards the end of the firearm's barrel, as it is path of least resistance. Additionally, the cartridge case swells until it is supported directly by the chamber, which surrounds the cartridge and is made of a rigid material. Cartridge cases are designed to be thin walled and are constructed of malleable materials such that the expanding cartridge case seals against the walls of the chamber, preventing hot gases from moving rearward around the cartridge case and towards the user.
With auto-loading pistols, and other non-revolving handguns such as single shot pistols and multi-shot derringers, the chamber is part of the barrel. As a result, once the cartridge has expanded to seal against the walls of the chamber, the only place the hot propellant gases can go is down and out of the barrel. With conventional revolvers, the chambers are part of the revolving cylinder, not the barrel. Additionally, in order to allow the cylinder to reliability rotate under adverse conditions, a certain gap is required between it and the barrel. This gap is commonly referred to as the barrel-cylinder gap and for a typical revolver it measures approximately between 0.005 and 0.015 inches (though there are a few exceptions to this range). It is worth noting that although unusual, there are firearms other than revolvers in which the barrel and chamber are separate components, such as rifles which have sliding, pivoting or rotating chambers, which may also benefit from the disclosed invention. There is also a frame-cylinder gap, for similar reasons as described above, which is in fluid communication with the barrel-cylinder gap.
The propellant gases which leak from the barrel-cylinder gap and the associated frame-cylinder gap are hot enough to burn the user if proximate to this region. In the case of extremely powerful magnum cartridges, being exposed to the gases leaking from the barrel-cylinder gap can severely damage, and even sever, finger digits.
Additionally, if the revolver is not very precisely manufactured and assembled such that the barrel is nearly perfectly aligned with the chamber being fired, pieces of the projectile can be sheared off as it enters the barrel and cause injury to the user. The phenomenon of pieces of the projectile being sheared off due to a misalignment between the barrel and cylinder chamber is commonly referred to as spitting.
There have been past attempts to seal the barrel-cylinder gap, eliminating the hazards described above, by either moving the cylinder forward just before cartridge ignition such that it seals against the barrel (Savage Navy Model Revolver of 1861, as disclosed in patent US28331), by using specialty ammunition which contains an integrated seal (such as Soviet PZAM, SP-3, and SP-4 ammunition), or a combination of both (Nagant M1895 Revolver, as disclosed in patent GB14010). In the cases where the cylinder is moved to seal against the barrel, while the seal tends to be secure and effective, the mechanism necessary for such movement adds to the complexity and size of the revolver's systems and any complexity inevitably increases risk of unpredictable failure. As with any firearm, an unpredictable failure, at the wrong moment, could cost a user vital time either as a total malfunction or even is merely adding surprise to the user's sensory input. While seals integral to the ammunition may also serve adequately, they only work when given ammunition is purchased and used. What is needed, then is a simpler, more reliable redirection system which, ideally, has no or few moving parts to fail and is integral to the firearm itself.
The present invention is a non-relocating means of redirecting the hot propulsion gases, which leak from the gap between the barrel and cylinder of conventional revolvers, away from the user and in a safe direction.